Kieran Gibbs to miss Besiktas tie

Kieran Gibbs faces three weeks on the sideline with a hamstring injury.

Arsenal defender Kieran Gibbs will miss both legs of the Champions League playoff against Besiktas after being ruled out for up three weeks with a hamstring injury.

The left-back was hurt in Saturday's 2-1 win over Crystal Palace, Arsenal's opening match of the Premier League season.

Nacho Monreal will likely come on as a replacement.

Centre-back Laurent Koscielny has shrugged off an Achilles problem and midfielder Mathieu Flamini returns after missing the Palace match, but forward Yaya Sanogo (hamstring) did not travel.

German World Cup winners Mesut Ozil, Per Mertesacker and Lukas Podolski are all not yet to be involved, while goalkeeper David Ospina (thigh), Theo Walcott and Serge Gnabry (both knee) continue their rehabilitation.

Arsenal are looking to qualify for the group stage of the Champions League for a 17th straight season.